QuillBot vs Grammarly for Students and Thesis Writers

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QuillBot vs Grammarly looks like a question about features. For a thesis writer it is really three questions: which tool fits which stage, what your university allows, and where your unpublished text goes.

This guide is based on official product pages, help centers and policy pages, read in November 2026. It is not a hands-on test. If you want QuillBot’s full feature rundown, read our QuillBot review for 2026. This post stays on the decision a student or thesis writer has to make.

First, a naming note: Grammarly the product, Superhuman the company

In October 2025 the company announced it was changing its company name to Superhuman, while saying “the Grammarly product will still exist.” That is still how the official pages read. The plans page is titled “Grammarly Prices and Plans”, and the footers name Superhuman Platform.

The current privacy policy names “Superhuman Platform Inc. (formerly Grammarly)”. So you still buy Grammarly, but your contract and data questions now sit with Superhuman. Grammarly Pro also bundles an assistant called Superhuman Go, which is why that name appears on student pages.

QuillBot vs Grammarly at a glance

Everything below comes from each company’s own pages. Where a page was silent or unclear, the table says so.

What matters to a thesis writer	QuillBot	Grammarly
Full paid price	Premium: $8.33/month billed annually in the plan comparison (the plan card also shows $5.00)	Pro: $12/member/month billed annually, or $30 billed monthly
Free paraphrasing	125 words at a time, 2 modes, no daily cap on rephrases	Free tool page does not state a word limit; in-product “Rewrite full sentences” is Pro
Grammar checking	Basic free; advanced on Premium; 6 languages on Premium	Spelling and grammar free; advanced clarity and tone on Pro; more than 20 languages
Plagiarism check	Premium only, 25,000 words/month, word packs extra	Pro only, against web pages and ProQuest academic databases, per Grammarly
AI detection	1,200 words per scan and 10 scans/day free; unlimited on Premium; English only	Public detector page says free; plans table lists it under Pro
Citations	Free, no sign-in, exports to Word, BibTeX, CSL-JSON	Free generator; citation consistency checks on Pro
Student discount	Student pricing page exists but could not be read; check it directly	50% off Pro for a limited time, verified by SheerID
Word	Add-in for Windows, Mac and Word online	Through the Windows and Mac desktop app
Google Docs	Through the Chrome extension sidebar	Through the browser extension
Writing-process record	Not found on the pages read	Authorship, on Free and Pro

Pricing as of November 2026

All prices are in USD and come from the official pages named below. Check again at checkout, because both companies run promotions.

Grammarly

• Free: $0, with 100 AI prompts a month.
• Pro: $12 per member per month billed annually, or $30 billed monthly, with 2,000 prompts per member per month. Grammarly’s help pages also mention quarterly billing, but the pricing pages read for this guide did not show a quarterly price.
• Enterprise: no price shown, contact sales.

The plans page shows $12 without a billing period, so the Pro page is the clearer source. The plans page also offers a free trial with an email reminder two days before it ends.

QuillBot

• Free: $0, no card required.
• Premium: the Premium page shows both $5.00 and $8.33 per month billed annually. The comparison section lists $8.33 only, so treat $5.00 as a possible promotion until checkout confirms it.
• Team: no price shown; teams of 5 or more get a discount through QuillBot’s business team.

A QuillBot blog FAQ last modified in February 2026 lists $99.95 a year, $39.95 every three months and $19.95 monthly. That page is older and the current Premium page shows only annual billing, so confirm shorter terms before planning around them. QuillBot lists a 3-day money-back guarantee for new users on Premium.

Student and education discounts

• Grammarly: its support page says “For a limited time, eligible students can get 50% off Grammarly Pro through SheerID verification”, with a separate link for graduate students. It covers one subscription period, cannot be combined with other offers, and does not apply to App Store or Google Play purchases. If that discount applies to the annual rate, it works out near $6 a month for that period; confirm at checkout.
• QuillBot: the site has a student pricing page, but it could not be retrieved for this guide, so its terms are not confirmed here. The Premium page mentions no student plan, and a help article says QuillBot cannot offer special discounts on request but does run periodic sales.
• University licences: Grammarly for Education is sold to institutions, so ask your library or IT service whether you already have access. Grammarly’s Pro FAQ says Pro is not currently available to Education customers, which means a campus licence may not look the same as a personal plan.

Feature by feature, for academic writing

Grammar checking and proofreading

Both check grammar, spelling and punctuation for free. Grammarly Free also covers conciseness and tone detection, and Pro adds advanced clarity and tone suggestions. QuillBot offers basic fixes free and what it calls advanced recommendations on Premium.

Edge: Grammarly. It lists conciseness and tone detection on its free plan, and support for more than 20 languages against QuillBot’s 6 on Premium. Neither tool knows your discipline, so reject any suggestion that changes a technical term or a hedged claim.

Paraphrasing

This is QuillBot’s home ground. Its Paraphraser allows 125 words at a time on the free plan with two modes, Standard and Fluency. Premium removes the input limit and adds modes including Academic, which QuillBot says “expresses text in a technical and scholarly way”.

Grammarly’s Paraphraser offers six preset styles and custom instructions. Its page also gives clearer academic guidance than QuillBot’s: always cite the source, and review AI rewrites because they may miss nuance.

Edge: QuillBot on modes and control. Edge: Grammarly on guidance. Using either on someone else’s text does not remove the need to cite it.

Citation help

QuillBot’s Citation Generator works without signing in and exports to Word, BibTeX or CSL-JSON. BibTeX matters if you write in LaTeX. QuillBot claims “100% accurate citations”, yet the same page shows “Missing information” tags, so check every entry against your style guide.

Grammarly’s free generator covers APA, MLA and Chicago, and Grammarly Free can generate citations on compatible source sites. The plans page lists “Keep your citations consistent” as a Pro feature. Edge: QuillBot for exports. Your reference manager should still be the main record for a thesis, since neither tool replaces one.

Plagiarism checks

Both charge for this. Grammarly says it checks against “over 16 billion web pages and academic papers in ProQuest’s databases”. The plagiarism page itself states no word limit. QuillBot says it scans “a wide range of sources”, without naming them on the pages read here, and allows 25,000 words a month with word packs available.

Edge: Grammarly, because it discloses more about its sources. Neither check equals what your university runs. Institutional similarity tools can compare against their own repositories, so a clean vendor report does not predict your official score.

AI detection and its limits

Grammarly says its detector “achieves 99% detection accuracy” and ranks first on the RAID benchmark. That is a vendor claim, not something this guide endorses. The same page says “No AI detector is 100% accurate”, and that detection “should never be used as a standalone verification method”.

QuillBot’s detector returns a 0 to 100% estimate, supports English only for now, and gives no accuracy figure on its page. It concedes that “the more advances are made in AI models, the less any AI detector tool will be able to distinguish” the two. QuillBot’s help center lists 1,200 words and 10 scans a day on free.

One conflict to note: Grammarly’s public detector page presents the tool as free with no sign-up, while the plans table marks “Detect AI generated text” as unavailable on Free. The likely reading is a free public tool plus a Pro in-product version, but no page read here states that.

False positives: why a score proves little

• A Stanford paper from 2023 by Liang and colleagues reported that seven detectors misclassified human-written TOEFL essays as AI-generated at an average rate of 61.22%. Detectors have changed since, but the finding is why non-native English writers should be careful.
• Vanderbilt University disabled Turnitin’s AI detector in 2023. It noted that even a claimed 1% false positive rate could mean about 750 of its 75,000 papers wrongly flagged.
• Johns Hopkins says it disabled Turnitin’s AI detection “due to reports of false positives”.

Practical takeaway: do not treat a low score as protection or a high score as guilt. If you are ever questioned, drafts and version history are more useful than a percentage from a different vendor’s tool.

Authorship: where Grammarly has no direct match on the pages read

Grammarly Authorship is opt-in and records whether text was typed, pasted or AI-assisted. It works in Google Docs with the extension, Word with the desktop app, the Grammarly Editor and Canvas submissions, and it is on both Free and Pro. Grammarly says reports go to no one unless you create and share them.

This can help if a supervisor asks how a chapter was written. It does also mean more of your process is being recorded, so weigh that against the privacy section below.

Long documents, Word and Google Docs

A thesis breaks tools built for short essays, so the limits matter more here than on most comparison lists.

Grammarly limits

• Its limitations page lists 100,000 characters per check in the web Editor, including spaces. At an estimated six characters per word, that is roughly 16,000 words, so split long files by chapter.
• Uploads top out at 100,000 characters and 4 MB. PDF, LaTeX and Markdown uploads are not supported.
• The Windows and Mac apps have no Grammarly character limit beyond your text editor’s.
• The account cap is 300 documents or 150,000 words per 30 days, and 100 documents or 50,000 words per 24 hours. An 80,000-word thesis would need at least two days on that basis.

QuillBot limits

• Premium removes the Paraphraser input limit, which still means working passage by passage if you want to read each change.
• The Summarizer caps at 1,200 words free and 6,000 on Premium.
• The Plagiarism Checker allows 25,000 words a month, so an 80,000-word thesis would need more than three months of allowance or extra word packs.
• The pages read here state no word limit for grammar checks on a full document. Test one long chapter before you rely on it.

Integrations

• Word: QuillBot for Word is a free sidebar add-in for Word on the web, Windows and Mac, with Paraphraser and grammar tools. Grammarly reaches Word through its Windows and Mac app.
• Google Docs: both use a browser extension. Grammarly offers real-time feedback, and QuillBot opens a sidebar from its extension.
• Overleaf and LaTeX: neither company’s pages read here confirm support. If you write in LaTeX, Grammarly’s upload limit above is a real obstacle, so test before paying.

Privacy and data use for unpublished thesis text

An unpublished chapter may hold original findings, participant quotes or data covered by an ethics approval. Read this section before pasting any of it into either tool.

Grammarly (Superhuman)

• Its training control page says Product Improvement and Training is on by default for individual accounts, including Free. You can turn it off in account settings. Accounts bought through Sales, including Education, are off by default.
• Its privacy FAQ says “We do not sell your content”. Documents in the Grammarly Editor stay until you delete them.
• The privacy policy, effective July 6, 2026, does not apply to content in organization-managed accounts. Those follow your institution’s contract.
• Grammarly says text typed in Grammarly is not indexed on the web, so its use should not itself create a web match.

QuillBot

• Its Trust Center says “you retain all rights to your text” and “we do not and will not sell your data”. It also says inputs are used to provide and train the service, except for Team Plan users, whose text inputs are not used for training.
• A November 2025 policy note says extension users have separate controls for storing inputs and for training, and that storage is on by default. The pages read here give no storage period and do not state the default training setting for a new account, so check the toggle yourself.
• QuillBot says Plagiarism Checker uploads are used only to run and access reports, and go only to the vendors needed for those checks.
• It also says it does not intentionally train on sensitive personal information, while noting that large datasets may still contain such details.
• QuillBot’s main privacy policy page could not be retrieved for this guide, so read it directly before uploading sensitive work.

A third-party warning is worth reading too. Abertay University’s student guide says that by using some QuillBot functions “you are giving Learneo (parent company) the right to display that content on CourseHero”. That is the university’s reading, and QuillBot’s pages read here do not state it, so compare it against QuillBot’s current terms.

Edge: Grammarly, slightly, because its pages state the default and the setting path more plainly. For either tool, the safe rule is the same: remove participant data and unpublished results before pasting, turn training off, and ask your ethics office if your approval limits third-party processing.

Academic integrity: check this before you buy anything

University rules differ widely, and they can differ between programs at the same university. A tool being sold to students does not mean your program allows it.

• A University of Melbourne assessment page from its BEL+T team names QuillBot alongside ChatGPT: using such software “to generate material for assessment” and presenting it as your own is not submitting your own work.
• Abertay University says QuillBot includes capabilities “some of which do not align with University frameworks and policies”, and that your assessment brief decides whether GenAI is allowed and must be acknowledged.
• Both vendors also offer humanizer tools. Using one to make AI text pass a detector is hard to defend under most integrity policies, whatever the marketing says.

Before you start, get these answers in writing, from your graduate school policy and your supervisor:

1. Is grammar and spelling correction allowed without declaration?
2. Are AI paraphrasing or rewriting tools allowed, and on which parts of the thesis?
3. Do you need to declare tool use in your thesis or a submission form, and in what wording?
4. Does your ethics approval or data agreement limit uploading text to third parties?

If the answer is unclear, stick to spelling and grammar correction you can explain, and keep your drafts.

Stage-by-stage thesis workflow: which tool fits where

The answer changes by stage, and at some stages the right tool is neither.

Stage	Best fit	How to use it safely
Notes and reading	Neither as a core tool; QuillBot Summarizer optional if allowed	Read what you cite. Keep your own notes in your own words.
References	QuillBot Citation Generator or Grammarly’s free generator, plus a reference manager	Check each entry against your style guide.
Drafting	Neither by default	Write first, in your own words, so your voice and argument exist before any tool touches them.
Editing your own draft	QuillBot for a stuck sentence, if your policy allows	Only on your own text. Compare to the original and undo anything that shifts meaning.
Supervisor rounds	Grammarly for clarity; Authorship if a record helps	Do not let suggestions flatten careful hedging.
Final proof	Grammarly, chapter by chapter	Accept changes one at a time, then read a printed copy.
Before submission	Your university’s official check	A vendor report is optional and does not replace it.

Where a thesis workspace fits

Neither tool tracks the thesis itself. That job belongs in a planning space, which is covered in our guide to a Notion thesis template. Our Thesis Writing PRO template lets you plan chapter by chapter, keep sources and notes in a literature matrix, track data collection and log advisor feedback.

It works on the free Notion plan. A useful habit to add yourself is one short log per chapter: which tool you used, on what, and when. That makes any declaration your university asks for much easier to write.

Who should choose which, and who should skip both

Choose Grammarly if

• You write your own drafts and want careful proofing and clarity edits on whole chapters.
• You want a writing-process record or work in more than one language.
• Your university offers a licence or you qualify for the current student discount.

Choose QuillBot if

• Your policy allows paraphrasing tools and you often get stuck on sentence phrasing.
• You want a free citation export to BibTeX or a Word add-in with paraphrasing built in.
• Price is the main factor and you do not qualify for Grammarly’s discount.

If that sounds like you, start with QuillBot’s free plan and only upgrade if the 125-word limit gets in your way.

Do not buy either if

• Your program bans these tools or your ethics approval rules out third-party processing.
• You only need a spelling check, which Word, Google Docs and both free plans already cover.
• You hope a tool will make a weak argument or AI-written text acceptable. It will not, and it can put your degree at risk.

QuillBot vs Grammarly FAQ

Is Grammarly now called Superhuman?

The company is. Official pages name Superhuman Platform Inc. (formerly Grammarly), while the writing product is still called Grammarly, with Grammarly Pro as its paid plan.

Which is better for a thesis, QuillBot or Grammarly?

For final proofing of your own chapters, Grammarly fits better. For rephrasing your own stuck sentences where that is allowed, QuillBot fits better. Check your university’s policy first, since it can rule either use out.

Is using QuillBot or Grammarly cheating?

It depends on your institution, program and how you use the tool. Spelling correction is often treated differently from AI paraphrasing or generation, but only your own policy and supervisor can give the answer that counts.

Can these AI detectors prove my writing is human?

No. Grammarly itself says no detector is 100% accurate and that results should not stand alone. Drafts, notes and version history are better evidence of your process.

Do QuillBot and Grammarly use my thesis text for training?

They can, depending on settings and plan. Grammarly says training is on by default for individual accounts, with an off switch. QuillBot says it trains on inputs, excluding Team Plan users, and gives account holders a control in the extension settings.

Is there a student discount?

Grammarly lists 50% off Pro for one subscription period through SheerID, marked as limited time. QuillBot has a student pricing page whose terms could not be confirmed here, so check it and compare at checkout.

Can I check a whole thesis for free?

Not for plagiarism, since both tools place that check behind a paid plan. Free grammar checks can work chapter by chapter, and your university’s own similarity service should be your final check.